Disc drives for use in reading from and/or writing to optical and magneto-optical discs are often stored vertically in a tower enclosure. FIGS. 1 and 2 show views of a conventional tower enclosure 10 including a plurality of disc drives 12 for reading data from and/or writing data to a plurality of discs. The discs 14 may be transferred from a cartridge 16 into respective disc drives 12 of the tower enclosure 10 one at a time. In particular, the robotic arm 20 may lift a disc 14 off of the cartridge 16, and transfer it to an open tray 22 of a disc drive 12. This individual disc transfer process may continue until all drives 12 in the tower enclosure 10 have been loaded.
In some tower enclosures, read/write operations do not begin until discs have been loaded into all drives as described above, thus resulting in wasted time as loaded drives remain idle during the disc-loading process. Similarly, upon completion of read/write operations, the robotic arm 20 may return the discs 14 from the disc drives 12 to the cartridge 16 one of the time, again resulting in wasted time.